Valve assembly and limit switch assembly therefor
AssigneeSchneider Electric Systems USA, Inc.
InventorsStéphane Marc Louis Hernu, Jonathan Dostert
Life of this patent
Estimating the term…
Abstract
A valve assembly includes a valve, an actuator for opening and closing the valve, and a positioner for controlling the actuator. At least one limit switch assembly is mounted between the positioner and the actuator. The limit switch assembly connects the actuator and positioner so that movement of the actuator valve is conveyed to the positioner through the limit switch assembly. The limit switch assembly is configured to provide a limit signal when the valve is in one or more limit positions. The limit switch assembly has a calibration mechanism for adjusting the one or more limit positions using an input member accessible from outside of the limit switch housing when the limit switch is installed in the valve assembly.
Claims28
A limit switch assembly configured to be operatively installed in a valve assembly, the valve assembly comprising a valve, an actuator movable to selectively open and close the valve, and a positioner for controlling movement of the actuator, the limit switch assembly comprising:
- a housing defining a sensor cavity and having a proximal end wall and a distal end wall spaced apart from one another along a feedback axis;
- and
- a limit position sensing assembly received in the sensor cavity comprising:
- a linking pin movably connected to the housing for movement with respect to the housing through a range of motion including at least one limit position, the linking pin extending along the feedback axis and having a proximal end portion and a distal end portion spaced apart from one another along the feedback axis, the proximal end portion of the linking pin being configured for being operatively connected to the actuator such that movement of the actuator drives corresponding movement of the linking pin through the range of motion;
- and
- at least one position sensor configured to detect when the linking pin is positioned in the at least one limit position;
- wherein the proximal end portion of the linking pin is exposed through the proximal end wall of the housing for being operatively connected to the actuator and the distal end portion of the linking pin is exposed through the distal end wall for being operatively connected to a feedback shaft of the positioner to operatively install the limit switch assembly in the valve assembly, and wherein the limit switch assembly is received between the positioner and the actuator when the limit switch assembly is operatively installed in the valve assembly such that the proximal end wall is located adjacent the actuator and the distal end wall is located adjacent the positioner and the linking pin operatively links the actuator to the feedback shaft of the positioner to drive movement of the feedback shaft in response to movement of the actuator.
A limit switch assembly configured to be operatively installed in a valve assembly, the valve assembly comprising a valve and an actuator movable to selectively open and close the valve, the limit switch assembly comprising:
- a housing defining a sensor cavity;
- a limit position sensing assembly received in the sensor cavity comprising:
- a feedback member configured to be operatively connected to the actuator such that movement of the actuator drives movement of the feedback member through a range of motion including at least one limit position;
- and
- at least one position sensor configured to detect at least one position of the feedback member in the range of motion;
- and
- a calibration mechanism for adjusting a relative position between the feedback member and the at least one position sensor to operatively align the at least one position sensor with the feedback member for detecting the position of the feedback member in the at least one limit position, the calibration mechanism comprising an input member movably mounted on the housing outside the sensor for movement in response to an input force and a calibration linkage extending through the housing and being operatively connected to the limit position sensing assembly and the input member to adjust said relative position between the feedback member and the at least one position sensor in response to movement of the input member.
Dependencies are inferred from the claim text.